Device for locking a sliding body, and particularly a retractable road boundary mark

ABSTRACT

A device for locking a sliding body, such as a retractable road boundary-mark, in at least two predetermined positions towards which the device is urged by a controller. The device includes a locking rod extending parallel to a sliding axis of the sliding body and rotatable about a longitudinal axis thereof. The locking rod has a plurality of transverse notches whose number and mutual distance along the rod are equal to the number and the mutual distance of the predetermined positions and which are angularly spaced from each other about the longitudinal axis of the rod.

TECHNICAL FIELD

The present invention relates to a device for locking a sliding body,and more particularly a retractable road boundary-mark.

BACKGROUND ART

It is already known that the function of a boundary-mark consists intemporarily closing a space to vehicles while letting pedestrians crosswhen it is in its raised position or when it is protruding above theground, and to enable authorized people to put their car in the space inquestion once the boundary-mark has been retracted into the ground byhand for example. Various systems for locking this kind of boundary-markin a raised and/or a lowered position are already known, but they arenot satisfactory particularly because they are not reliable enough, theyare fragile and can be forced by hooligans, while another disadvantagearises from the fact that users may fail to put the boundary-mark backin its raised position once they have got over it.

The present invention therefore aims at providing a locking device ofthe above-mentioned type which overcomes the disadvantages of knownsystems and which is solid and reliable while being relativelyinexpensive.

Another purpose of the invention is to provide a device which preventsthe users from leaving the boundary-mark in its retracted position, thatis in its lowered position once their car has gone over the device.

A further object is to protect such device from the harmful effect ofoutside agents such as surface waters, dust, sand and gravel.

SUMMARY OF THE INVENTION

According to the invention, the above and other aims which will appearhereinafter, such as the automatic elimination of backlash and wear, areachieved thanks to a device of the above-mentioned type characterized inthat it comprises a locking rod which extends parallel to the slidingaxis of the sliding body and which may rotate about its longitudinalaxis, but cannot move parallel thereto, said locking rod presenting aplurality of transverse notches whose number and mutual distance alongsaid locking rod are respectively equal to the number and the mutualdistance of said predetermined positions of the sliding body whosebottom is convex and is linked with the side cylindrical surface of thelocking rod, and which are angularly spaced from one another about thelengthwise axes of said locking rod when they are viewed from their axisdirection, without two successive notches overlapping, and a device witha bolt attached to said sliding body and capable of being urged intosaid notches by means of a spring force; and means for rotating saidlocking rod around its axis so as to bring it successively intopredetermined angular positions into which one of the transverse notchesof the rod, viewed from the rod axis direction, opens outwardly in thedirection of the bolt which is meant to enter into said notch.

It shall be easily understood that with such device, the bolt is pushedby a spring force into one of the notch of the locking rod according tothe invention for each predetermined position of the sliding body, forexample for the raised and the lowered positions in case of aretractable road boundary-mark. If said rod is then rotated, the contactpoint between the bottom of the convex notch and the bolt end goes awayfrom the axis of the rod, and the bolt is outwardly driven as it slideson the bottom of the notch. Then there is a time when the bolt is nolonger held back by the notch and when the it can slide along agenerator of the cylindrical side surface of the locking rod, under theinfluence of the control unit which acts upon the sliding body until itmeets the following notch of the rod into which it enters so as to belocked, a process which stops the sliding body attached to the bolt frommoving.

According to one advantageous embodiment of the present invention,particularly concerning the machining of the locking rod, each notch ofsaid rod is radially delimited by a bottom made of a cylindricalrevolution surface whose axis, parallel with the locking rod, is placedbetween said axis and the side surface of the rod or beyond, and,axially by two plane shoulders perpendicular to the locking rod axis,said shoulders being crescent-shaped and extending from the arc of acircle of the locking rod cylindrical side surface and the arc of thecylindrical surface composing the bottom of the notch. For greaterconvenience, the imaginary straight line joining up both intersectingpoints of said arcs of a circle will be named "chord of the notch" inthe following description.

In the most simple case where only two predetermined positions of thesliding body are provided, for example a low retracted position and ahigh protruding position of a retractable boundary-mark, the locking rodof the device according to the invention consists of two transversenotches which are for example offset according to a 90° angle when theyare viewed from the rod axis direction. That means that it is a quarterturn rotation of the rod into one direction or the other which willenable a road boundary-mark to go from one notch to the other or viceversa, that is to say from the low position to the high position orconversely.

As for the above-mentioned bolt device, it advantageously comprises aguide roller installed on the sliding body perpendicularly with itssliding axis, the actual bolt which is assembled so that it can slideinside the guide roller and whose free end is dimensioned so as to beable to enter the transverse notches of the locking rod, a pressurespring inserted between the bottom of the guide roller and the actualbolt, and a catch which is solid with the bolt and slides in anelongated slot provided for in the side wall of the guide roller andwhich extends parallel to the axis thereof. It is understood that it issaid pressure spring which is meant to push the free end of the boltinto the respective notches of the locking rod, whereas the catchcooperating with the elongated slot prevents the bolt from turning inits guide roller and delimits the axial stroke. It should also be notedthat such solution makes it possible to eliminate backlash and wear ofthe bolt and the locking rod automatically, as well as to correctlinearity faults of the rod, such faults being originated for example bythe rod buckling.

Preferably, the abovementioned means rotating the locking rod around itsaxis comprise a prismatic tip which protrudes at one of the end of saidrod and whose edges are parallel to the rod axis, and an operating keyended with a female hollow imprint reproducing the cross section of theshape of said prismatic tip. This tip having a triangular cross sectionfor example, can be attached to the locking rod, but it can also be partof the cylinder which is assembled so as to be interchangeable on one ofthe end of the rod, so that the key can be easily and regularly changed,thereby preventing non authorized person from using the boundary-mark.

Advantageously, an access plate is fixedly placed beyond the prismatictip of the locking rod perpendicularly to the axis of the latter, suchaccess plate being provided with an opening in line with the rod, saidopening being designed for the introduction of the operating key andhaving a shape which corresponds to that of the outline of the actualkey. Therefore the locking rod can only be actuated with a key whichcorresponds to the key which is used, not only thanks to its inner shapebut also to its outline. Besides, such access plate protects the lockingdevice from the introduction of any forcing tool.

Moreover, according to one advantageous embodiment of the invention, ifthe outline of the operating key when it covers the prismatic tip of thelocking rod is in line with the opening provided in the access plate foronly one of the predetermined angular positions of the locking rod, andtherefore of the sliding body, the key will only be withdrawn from theopening of the access plate if the locking rod has been previouslyplaced in the predetermined position which allows this operation. As fora two-positions road boundary-mark, one should obviously choose asunique angular position enabling to withdraw the key the position whichcorresponds to the raised position of the boundary-mark so that the userwill only be able to withdraw his key if he takes care to put theboundary-mark back in its raised position.

This advantageous characteristic of the various shapes which can begiven to the imprint of the key and to its outline, together with thevarious possible angular relative positions of the locking rod and theaccess plate opening make it possible to multiply the conceivableconfidentiality combinations endlessly, thereby providing a safety whichis still unequalled today.

According to the invention, the device is advantageously protectedagainst outside agents such as surface waters, dust and sand thanks toan automatic shutter which is situated above the locking rod at groundlevel.

Preferably, the locking rod according to the invention comprises a notchfor holding and returning to an angular position whose bottom consistsin a plurality of flat surfaces, each of them corresponding with one ofthe predetermined angular positions which is to be held, and extendinginto space parallel to the chord of the corresponding notch, and intowhich enters a L-shaped lever arm which returns to the bottom of thenotch thanks to a spring, the other arm of said L-shaped lever beingarticulated on a fixed part. This type of locking mechanism holds thelocking rod in each one of the angular positions corresponding with oneof the predetermined positions of the sliding body as well as it returnsit into the nearest position.

As for the controlling device of the sliding body motions, that is forexample of the road boundary-mark, it could be the pneumatic mechanismwhich is described in the French patent 86 05310 dated Apr. 4 1986, butit could also be a plain spring which is pressed by pushing theboundary-mark so as to place it into its lowered position and whichsprings back when the locking device according to the invention allowsthe boundary-mark to return to its raised position.

It has been noted from what has been said so far that the solutionsproposed by the present invention make it possible to reach theobjectives which were aimed at.

The following description which is in no way aimed at limiting theinvention, will enable to understand how the present invention may work.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 1a are an exploded perspective views of a road boundary-markusing the locking device according to the invention;

FIG. 2 shows a side sectional drawing of the locking rod of the deviceshown in FIG. 1, according to line II of such figure;

FIG. 3 as well as FIG. 4 shows the device with a bolt acting on thelocking rod of the figure;

FIG. 4 is a cross-section of the bolt of FIG. 3 taken along line IV--IV;

FIGS. 5 to 8 show cross-sections of the locking rod of FIG. 2, takenrespectively along the lines V--V to VIII--VIII of the figure;

FIG. 9 shows a plate leading to the locking rod of the device accordingto the invention, taken along the line IX--IX of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

In order to explain the operating method of the locking device which hasjust been described, it is inferred that the retractable boundary-mark(1) and the slide unit (2) are in a raised position and that the angularposition of the locking rod (7) is such as the upper notch (17a) of saidrod is directed toward the bolt (13), as it is shown on the compositionof FIGS. 2 and 3, so that the free end of the bolt enters thereto thanksto the spring (14). If one were to try to move the road boundary-mark(1) vertically, nothing would happen since the bolt (13) which is solidwith the boundary-mark (1) thanks to the slide unit (2) and insertedinto the notch (17a) of the rod (7) prevents the unit comprising theboundary-mark (1) and the slide unit (2) from moving vertically.

If the user then opens the door (30) and inserts the key into theopening (27) of the access plate (26), the female recession of saidplate covers the prismatic tip (19) of the locking rod (7), as it hasalready been explained hereabove. Then, the user makes his key rotate bya quarter turn in the direction imposed by the stops (20) of the rod(7), and the mechanism consisting of the lever (21), the draw spring(24) and the flat surfaces (25) causes the rod (7) to go into the otherextreme position. Meanwhile, the free end of the bolt (13) slides on thecylindrical bottom of the notch (17a) and the bolt (13) is pushedoutside towards the spring (14). When it has completely come out of thenotch (17a), the slide unit (2) can move freely downward thanks to itsdriving means which may consist of a manual pressure on theboundary-mark (1) towards a pressure spring, the free end of the bolt(13) sliding along one of the generators of the rod (7) until it entersthe lower notch (17b) thanks to the spring (14), therefore locking thedownward motion of the slide unit (2) and thus of the boundary-mark (1)which is then retracted. The unit consisting in the boundary-mark (1)and the slide unit (2) cannot move upward since the bolt (13) is caughtinto the notch (17b) of the locking rod (7).

Then the user may drive out, but if he carelessly leaves theboundary-mark in this position, he will not be able to get his key backsince it is locked by its lateral snug (28) underneath the access plate(26), and he will only be able to take it off by turning it a quarterturn in the direction opposite to that transmitted to the key andtherefore to the locking rod (7) by the prismatic tip (19).Simultaneously with this operation, the bolt (13) is pushed out of thelower notch (17b) of the rod (7), the free end of the bolt slides alongone of the generators of the rod (7) thanks to the driving mechanismwhich tends to make the slide unit (2) and the boundary-mark (1) andtherefore the bolt (13) attached to the latter go upward, and the bolt(13) is locked into the upper notch (17a) of the the rod (7) which isthen on its way.

The user can take his key off, the snug of said key lining up with thelead-in notch (29) of the access plate (26) and the unit is back intoits initial position where the boundary-mark (1) is projecting above theground for obstructing the way. It is obvious that without departingfrom the present invention, many modifications may be made to theembodiment described hereabove. For example, this device could includemore than two locking positions by providing an adequate number ofnotches (17) placed on precise points along the rod (7) and angularlyoffset so that once the bolt (13) has left one notch because of therotation of the rod (7) and when it slides along one generator of thelatter, it necessarily meets the notched into which it can be locked.

For a boundary-mark, it could be possible to provide positions offeringseveral heights. Moreover, the prismatic end (19) which designed forbeing covered by the key C could be formed on an interchangeablecylinder and no longer be attached to with the rod (7). Besides, othermeans than squares (20) could be used so as to limit the rotating strokeof the locking rod (7) as, for example, a fixed finger entering into aring groove provided for on 90° of the rod (7). The latter could befixed into the case (4) thanks to other means than the step bearing (8)and the bearing (9) and, moreover, the opening (27) outline of theaccess plate (26) could be different from the one which is representedin FIG. 9. It will be noted that when there are more than two lockingpositions, the number of flat surfaces (25) provided for in the notch(23) of the rod (7) and designed for locking the rod into each one ofthe positions should be equal to the locking positions, each flatsurface being parallel to the corresponding notch (17) chord.

I claim:
 1. A device for locking a sliding body in at least twopredetermined positions towards which the device may be urged by acontrol device acting on a locking body which extends parallel to asliding axis of the sliding body and which rotates around itslongitudinal axis but cannot move parallel thereto, the devicecomprising:a plurality of transverse notches formed on the locking rodand whose number and mutual distance along said locking rod arerespectively equal to a number and a mutual distance of saidpredetermined positions, said notches having a bottom which is convexand is linked with side surfaces of said locking rod, said notches beingangularly spaced from each other about the axis of said locking rod whenviewed from a lengthwise direction of the locking rod; and a bolt meanscooperative with said plurality of transverse notches and attached tosaid sliding body, said bolt means engaging said notches by a pressureof a spring such that the rotating of said locking rod around its axisbrings the bolt to the predetermined angular positions where one of saidtransverse notches opens outwardly toward said bolt means.
 2. The deviceaccording to claim 1, each one of the transverse notches is radiallydelimited by a bottom configured as a cylindrical revolution surfacewhose radius exceeds a radius of the rod and whose axis parallel to theaxis of said locking rod is situated between said axis and a lateralsurface of the rod and two plane shoulders perpendicular to the axis ofthe locking rod.
 3. The device according to claims 1, wherein two ofsaid transverse notches being spaced by a 90° angle from each other whensaid two of said transverse notches are viewed from the lengthwisedirection of said locking rod.
 4. The device according to claim 1,wherein said bolt means comprises:a guide roller fixed on said slidingbody perpendicularly to the sliding axis of the sliding body; a boltmember slidingly mounted inside said guide roller and whose free end isdimensioned so as to allow it to enter said transverse notches; apressure spring located between a bottom of said guide roller and saidbolt member; and a catch integral with the bolt member and slidable inan elongated slot in a side wall of the guide roller.
 5. The device ofclaim 1, further comprising:a prismatic tip protruding from an end ofthe rod and having edges parallel to the axis of the rod; and anoperating key having a female imprint matching a cross-section of ashape of said prismatic tip, said prismatic tip being part of a cylinderinterchangably mounted to the end of the locking rod.
 6. The deviceaccording to claim 5, wherein said operating key has an outline in linewith an opening of said access plate for only one given angular positionof said locking rod when said operating key covers said prismatic tip.7. The device according to claim 1, said sliding body being aretractable road boundary-mark, the device further comprising:anautomatically closing protection door positioned at generally groundlevel above said locking rod.
 8. The device according to claim 1,further comprising:a notch means for holding and returning to an angularposition, said notch means having a bottom formed of a plurality of flatsurfaces, each of said plurality of flat surfaces corresponding with oneof said predetermined angular positions and extending parallel to achord of a corresponding transverse notch, said notch means receiving anarm of a lever which resiliently returns to the bottom of said notchmeans.